/**
 * Copyright (C) 2011 Whisper Systems
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package com.appspot.eusms;

import android.os.Bundle;
import android.text.Editable;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

import com.appspot.eusms.crypto.InvalidPassphraseException;
import com.appspot.eusms.crypto.MasterSecretUtil;
import com.appspot.eusms.util.MemoryCleaner;
import com.appspot.eusms.util.TextSecurePreferences;

import com.appspot.eusms.R;

import org.whispersystems.textsecure.crypto.MasterSecret;

/**
 * Activity for changing a user's local encryption passphrase.
 *
 * @author Moxie Marlinspike
 */

public class PassphraseChangeActivity extends PassphraseActivity {

    private EditText originalPassphrase;
    private EditText newPassphrase;
    private EditText repeatPassphrase;
    private TextView originalPassphraseLabel;
    private Button okButton;
    private Button cancelButton;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.change_passphrase_activity);

        initializeResources();
    }

    private void initializeResources() {
        this.originalPassphraseLabel = (TextView) findViewById(R.id.old_passphrase_label);
        this.originalPassphrase = (EditText) findViewById(R.id.old_passphrase);
        this.newPassphrase = (EditText) findViewById(R.id.new_passphrase);
        this.repeatPassphrase = (EditText) findViewById(R.id.repeat_passphrase);

        this.okButton = (Button) findViewById(R.id.ok_button);
        this.cancelButton = (Button) findViewById(R.id.cancel_button);

        this.okButton.setOnClickListener(new OkButtonClickListener());
        this.cancelButton.setOnClickListener(new CancelButtonClickListener());

        if (TextSecurePreferences.isPasswordDisabled(this)) {
            this.originalPassphrase.setVisibility(View.GONE);
            this.originalPassphraseLabel.setVisibility(View.GONE);
        } else {
            this.originalPassphrase.setVisibility(View.VISIBLE);
            this.originalPassphraseLabel.setVisibility(View.VISIBLE);
        }
    }

    private void verifyAndSavePassphrases() {
        Editable originalText = this.originalPassphrase.getText();
        Editable newText = this.newPassphrase.getText();
        Editable repeatText = this.repeatPassphrase.getText();

        String original = (originalText == null ? "" : originalText.toString());
        String passphrase = (newText == null ? "" : newText.toString());
        String passphraseRepeat = (repeatText == null ? "" : repeatText.toString());

        if (TextSecurePreferences.isPasswordDisabled(this)) {
            original = MasterSecretUtil.UNENCRYPTED_PASSPHRASE;
        }

        try {
            if (!passphrase.equals(passphraseRepeat)) {
                Toast.makeText(getApplicationContext(),
                        R.string.PassphraseChangeActivity_passphrases_dont_match_exclamation,
                        Toast.LENGTH_SHORT).show();
                this.newPassphrase.setText("");
                this.repeatPassphrase.setText("");
            } else {
                MasterSecret masterSecret = MasterSecretUtil.changeMasterSecretPassphrase(this, original, passphrase);
                TextSecurePreferences.setPasswordDisabled(this, false);

                MemoryCleaner.clean(original);
                MemoryCleaner.clean(passphrase);
                MemoryCleaner.clean(passphraseRepeat);

                setMasterSecret(masterSecret);
            }
        } catch (InvalidPassphraseException e) {
            Toast.makeText(this, R.string.PassphraseChangeActivity_incorrect_old_passphrase_exclamation,
                    Toast.LENGTH_LONG).show();
            this.originalPassphrase.setText("");
        }
    }

    private class CancelButtonClickListener implements OnClickListener {
        public void onClick(View v) {
            finish();
        }
    }

    private class OkButtonClickListener implements OnClickListener {
        public void onClick(View v) {
            verifyAndSavePassphrases();
        }
    }

    @Override
    protected void cleanup() {
        this.originalPassphrase = null;
        this.newPassphrase = null;
        this.repeatPassphrase = null;

        System.gc();
    }
}
